// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_WIN_SCOPED_PROCESS_INFORMATION_H_
#define BASE_WIN_SCOPED_PROCESS_INFORMATION_H_

#include <windows.h>

#include "base/base_export.h"
#include "base/macros.h"
#include "base/win/scoped_handle.h"

namespace base {
namespace win {

    // Manages the closing of process and thread handles from PROCESS_INFORMATION
    // structures. Allows clients to take ownership of either handle independently.
    class BASE_EXPORT ScopedProcessInformation {
    public:
        ScopedProcessInformation();
        explicit ScopedProcessInformation(const PROCESS_INFORMATION& process_info);
        ~ScopedProcessInformation();

        // Returns true iff this instance is holding a thread and/or process handle.
        bool IsValid() const;

        // Closes the held thread and process handles, if any.
        void Close();

        // Populates this instance with the provided |process_info|.
        void Set(const PROCESS_INFORMATION& process_info);

        // Populates this instance with duplicate handles and the thread/process IDs
        // from |other|. Returns false in case of failure, in which case this instance
        // will be completely unpopulated.
        bool DuplicateFrom(const ScopedProcessInformation& other);

        // Transfers ownership of the held PROCESS_INFORMATION, if any, away from this
        // instance.
        PROCESS_INFORMATION Take();

        // Transfers ownership of the held process handle, if any, away from this
        // instance. Note that the related process_id will also be cleared.
        HANDLE TakeProcessHandle();

        // Transfers ownership of the held thread handle, if any, away from this
        // instance. Note that the related thread_id will also be cleared.
        HANDLE TakeThreadHandle();

        // Returns the held process handle, if any, while retaining ownership.
        HANDLE process_handle() const
        {
            return process_handle_.Get();
        }

        // Returns the held thread handle, if any, while retaining ownership.
        HANDLE thread_handle() const
        {
            return thread_handle_.Get();
        }

        // Returns the held process id, if any.
        DWORD process_id() const
        {
            return process_id_;
        }

        // Returns the held thread id, if any.
        DWORD thread_id() const
        {
            return thread_id_;
        }

    private:
        ScopedHandle process_handle_;
        ScopedHandle thread_handle_;
        DWORD process_id_;
        DWORD thread_id_;

        DISALLOW_COPY_AND_ASSIGN(ScopedProcessInformation);
    };

} // namespace win
} // namespace base

#endif // BASE_WIN_SCOPED_PROCESS_INFORMATION_H_
